How many plants?

That is one unusually sized space for a grow. 8 plants will grow there fine, if you prepare the space properly.

A 400 HPS won't cover the space well to the 6' ends, and then there's the heat.

A couple of 250's would light the space up well, and then there's the heat.

CFL's on some kind of rig to cover the space would also work. And then there's the heat.

Personally, I'd worry how you're going to vent the room

a 400 hps on a track might work out alright

If I used a 400 hps would i yield quality bud off eight plants?

Originally Posted by bluntmassa1

a 400 hps on a track might work out alright

How much bud would it yield for eight plants?

smokinrav has hit the nail on the head.
the area is a bit small for 500w of lighting, it is long and narrow, i am presuming when you open the door of the cupboard it is 6 feet wide x 2 feet deep in x 8 feet high, 500w will turn that space in to an oven.

i have a similarly shaped and slightly larger (long, narrow) closet that i cover with a combination of 400w of HPS and 216w of t5

temps stay below 82f with a 165 CFM 4" inline duct fan sucking from a carbon filter above the light, passive intake

i usually flower 5 to 7 plants at a time, depending on how big they're likely to get. it's easy to LST enough to make the space comfortable

How do you go about switching from 400w hps to 216w of fluorescents?

Originally Posted by WeeGogs

smokinrav has hit the nail on the head.
the area is a bit small for 500w of lighting, it is long and narrow, i am presuming when you open the door of the cupboard it is 6 feet wide x 2 feet deep in x 8 feet high, 500w will turn that space in to an oven.

The areas not too small (far from it) but ventilation is key.